Diagnostic Aids
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST procedures to ensure all electronic engine control systems are working properly and DTCs are no longer present.
The Accelerator Pedal Position (APP) sensor provides the Powertrain Control Module (PCM) with the driver's demand for power. The PCM determines the APP by processing input signals from the APP sensor. The APP signal is used in calculating desired fuel quantity, injection timing and injection control pressure.
Any detected malfunction of the APP sensor will not illuminate the CHECK ENGINE light at this time. An APP signal that is detected out of range high or low by the PCM will cause the engine to ignore the APP signal and will only allow the engine to operate at low idle. Perform this test when directed by QUICK TEST. This test is only intended to diagnose the following components and circuits:
- AP Sensor
- Wiring Harness Circuits; (AP, AP GND & VREF)
- Powertrain Control Module (PCM)